/*
 * Copyright 2014 Canonical
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors: Andreas Pokorny
 */

#include <drm/drm_prime.h>
#include <linux/virtio_dma_buf.h>

#include "virtgpu_drv.h"

static int virtgpu_virtio_get_uuid(struct dma_buf *buf,
				   uuid_t *uuid)
{
	struct drm_gem_object *obj = buf->priv;
	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
	struct virtio_gpu_device *vgdev = obj->dev->dev_private;

	wait_event(vgdev->resp_wq, bo->uuid_state != STATE_INITIALIZING);
	if (bo->uuid_state != STATE_OK)
		return -ENODEV;

	uuid_copy(uuid, &bo->uuid);

	return 0;
}

static struct sg_table *
virtgpu_gem_map_dma_buf(struct dma_buf_attachment *attach,
			enum dma_data_direction dir)
{
	struct drm_gem_object *obj = attach->dmabuf->priv;
	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);

	if (virtio_gpu_is_vram(bo))
		return virtio_gpu_vram_map_dma_buf(bo, attach->dev, dir);

	return drm_gem_map_dma_buf(attach, dir);
}

static void virtgpu_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
				      struct sg_table *sgt,
				      enum dma_data_direction dir)
{
	struct drm_gem_object *obj = attach->dmabuf->priv;
	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);

	if (virtio_gpu_is_vram(bo)) {
		virtio_gpu_vram_unmap_dma_buf(attach->dev, sgt, dir);
		return;
	}

	drm_gem_unmap_dma_buf(attach, sgt, dir);
}

static const struct virtio_dma_buf_ops virtgpu_dmabuf_ops =  {
	.ops = {
		.cache_sgt_mapping = true,
		.attach = virtio_dma_buf_attach,
		.detach = drm_gem_map_detach,
		.map_dma_buf = virtgpu_gem_map_dma_buf,
		.unmap_dma_buf = virtgpu_gem_unmap_dma_buf,
		.release = drm_gem_dmabuf_release,
		.mmap = drm_gem_dmabuf_mmap,
		.vmap = drm_gem_dmabuf_vmap,
		.vunmap = drm_gem_dmabuf_vunmap,
	},
	.device_attach = drm_gem_map_attach,
	.get_uuid = virtgpu_virtio_get_uuid,
};

int virtio_gpu_resource_assign_uuid(struct virtio_gpu_device *vgdev,
				    struct virtio_gpu_object *bo)
{
	struct virtio_gpu_object_array *objs;

	objs = virtio_gpu_array_alloc(1);
	if (!objs)
		return -ENOMEM;

	virtio_gpu_array_add_obj(objs, &bo->base.base);

	return virtio_gpu_cmd_resource_assign_uuid(vgdev, objs);
}

struct dma_buf *virtgpu_gem_prime_export(struct drm_gem_object *obj,
					 int flags)
{
	struct dma_buf *buf;
	struct drm_device *dev = obj->dev;
	struct virtio_gpu_device *vgdev = dev->dev_private;
	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
	int ret = 0;
	bool blob = bo->host3d_blob || bo->guest_blob;
	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);

	if (!blob) {
		if (vgdev->has_resource_assign_uuid) {
			ret = virtio_gpu_resource_assign_uuid(vgdev, bo);
			if (ret)
				return ERR_PTR(ret);

			virtio_gpu_notify(vgdev);
		} else {
			bo->uuid_state = STATE_ERR;
		}
	} else if (!(bo->blob_flags & VIRTGPU_BLOB_FLAG_USE_CROSS_DEVICE)) {
		bo->uuid_state = STATE_ERR;
	}

	exp_info.ops = &virtgpu_dmabuf_ops.ops;
	exp_info.size = obj->size;
	exp_info.flags = flags;
	exp_info.priv = obj;
	exp_info.resv = obj->resv;

	buf = virtio_dma_buf_export(&exp_info);
	if (IS_ERR(buf))
		return buf;

	drm_dev_get(dev);
	drm_gem_object_get(obj);

	return buf;
}

struct drm_gem_object *virtgpu_gem_prime_import(struct drm_device *dev,
						struct dma_buf *buf)
{
	struct drm_gem_object *obj;

	if (buf->ops == &virtgpu_dmabuf_ops.ops) {
		obj = buf->priv;
		if (obj->dev == dev) {
			/*
			 * Importing dmabuf exported from our own gem increases
			 * refcount on gem itself instead of f_count of dmabuf.
			 */
			drm_gem_object_get(obj);
			return obj;
		}
	}

	return drm_gem_prime_import(dev, buf);
}

struct drm_gem_object *virtgpu_gem_prime_import_sg_table(
	struct drm_device *dev, struct dma_buf_attachment *attach,
	struct sg_table *table)
{
	return ERR_PTR(-ENODEV);
}